


These Mother's Sons

by thedropoutandthejunkie (elenajames)



Category: Supernatural
Genre: Alpha Mary, Alpha Sam, Alpha/Beta/Omega Dynamics, Breeding, Double Penetration, F/M, Knotting, M/M, Mpreg, Omega Dean, Parent/Child Incest, Sibling Incest, Wishy Washy Anatomy
Language: English
Status: Completed
Published: 2016-05-04
Updated: 2016-05-04
Packaged: 2018-06-06 07:22:56
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 900
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6744919
Author URL: https://archiveofourown.org/users/elenajames/pseuds/thedropoutandthejunkie
Summary: <blockquote class="userstuff">
              <p>Dean's been waiting for the right alpha, only to find out the right one(s) are already there.</p>
            </blockquote>





	These Mother's Sons

**Author's Note:**

> Written for SPN Kink Bingo.  
> Square Filled: Double Penetration.

It’s a secret, what he and Mom have. At least, that’s what Dean thinks. Mary had welcomed her oldest into her bed when he first hit his heats, gentling him through them even though she hadn’t bred him properly. 

 

“You’ll find a nice alpha someday, baby. They’ll be glad to put a pup in your belly.” 

 

He clung to those words, dreaming of a faceless alpha who’d pet him and fuck him in turns, dreaming of a round belly with his alpha’s pup inside. 

 

Dean didn’t think that alpha would turn out to be Sam. Sixteen, and Sam hits his first rut hard, sweaty and hot and reeking of fertile alpha so that Dean’s mouth waters. Mary finds him standing outside his little brother’s bedroom door, jeans damp with slick and a flush in his cheeks as Sam’s rut spurs his body into heat. 

 

For a moment, Dean’s not sure what his mother will do; sure, they’ve been having sex ever since he presented, but Sam’s still a teenager even if he is an alpha. Mary steps closer, getting between Dean and the door so she can knock. 

 

“Sammy? It’s mom. Can I come in?” 

 

Sam grunts in answer, but Mary opens the door anyway. The smell of rut washes over them, making Mary rumble slightly and Dean’s body flash with warmth. There’s no warning before Sam’s out of the bed, pinning Dean to the wall and scenting all along his brother’s throat. 

 

“Shouldn’t be in here. Mom, he shouldn’t be -” Sam breaks on a growl, biting down on Dean’s neck and purring in satisfaction when the omega submits, tilting his head back. 

 

“Easy, Sam,” Mary coaxes, and the scent of her calm washing over them gets Sam to take a breath. She’s an alpha, sure, and his instincts won’t like that, but she’s still his mother. “He likes it gentle at first.” 

 

Dean tenses when Sam does, and he’s barely able to force himself to meet stunned hazel eyes. 

 

“You- you both-” 

 

“Who do you think’s been helping me with my heats?” Dean says it soft, dropping his gaze because he’s sure rejection is coming. What he gets instead is Sam’s mouth against his, and a long-fingered hand cradling his cheek. 

 

Together, Sam and Mary strip him down, their mother’s hands guiding Sam’s to all the places Dean loves to be touched, showing him just how to scratch and stroke and tease. Dean thinks he stops breathing when Sam pulls Mary in for a kiss, alpha instincts causing them to growl in each other’s mouths even as they tug at hair and clothing. 

 

Dean’s swept along by them, arranged in bed so he’s straddling Sam’s hips with Mary kissing along his shoulders. Sam’s cock is big, thick and long and intimidating, but two fingers are pushing up in him to test his slick and to stretch him a little before sliding free. 

 

“You can take it, baby,” Mary murmurs, helping Sam to line up and holding Dean’s hips as he slides down. He moans at the stretch, gripping Sam’s hands where they rest along Dean’s thighs. Sam reaches deep, nudging Dean’s cervix in a way that would hurt if he weren’t in heat; for now, it just makes his belly twinge, craving a knot and come and pups.

 

Warm slick slides in from behind, and Dean trembles as Mary gently nudges her cock in alongside Sam’s. She’s thinner and shorter, but it’s still more than he’s ever taken. 

 

“S’okay, Dean.” Sam pets Dean’s thigh and rolls his hips, the first drag of his cock in and out lighting up all of Dean’s nerves. He drops down so he’s face to face with Sam, feeling Mary grip his hips so she can thrust in, alternating with Sam until they hit a steady rhythm that keeps Dean full. 

 

“Think you can take us both,” Sam pants. “Keep Mom’s cock in you while I knot?” 

 

Dean shivers and groans, clenching around the cocks inside him and making the alphas grunt. “Please, please knot me, I need- I want-”

 

“Pups. You want pups, just like a good omega, don’t you big brother. And you’re not even gonna know whose they are, taking two alphas at the same time. Maybe you’ll get one of each, huh?” Sam’s mouth pours out filth, but Dean can feel his gut twist at the thought of carrying a baby for both Sam and Mom. 

 

Mary comes first, a warm surge of wet inside Dean that makes him whine. She draws out just as Sam shoves his cock in deep, knot swelling fast to keep his come inside. Knowing hands slide from Dean’s hips down to his belly. He can feel his eggs drop, urged along by Mary’s fingers, and Dean comes with a thin cry. 

 

“Good boy,” Mary murmurs, helping to settle him down over Sam’s chest. Long arms - boy thin but alpha strong - wrap around him and hold him close. Sam nips at his neck in warning before sinking his teeth deep, hard enough to mark and drawing a second orgasm out of the omega. 

 

“Gonna be so full, Dean.” Sammy sounds pleased and Dean sighs happily. Mary settles down alongside them until Dean falls asleep; she leaves them alone for their second round, and Dean’s pleasantly surprised when Sam invites her back in for the third. 

 

Maybe one of Dean’s pups will be hers after all. 


End file.
